Bottle closure assembly including a polyethylene composition

ABSTRACT

The present disclosure describes bottle closure assemblies which are made at least in part with a high density unimodal polyethylene. The bottle closure assembly includes a cap portion, an elongated tether portion and a retaining means portion. The retaining means portions engages a bottle neck or an upper portion of a bottle. The elongated tether portion connects at least one point on the cap portion to at least one point on the retaining means portion so as to prevent loss of the cap portion from a bottle.

This application claims the benefit of the filing date of U.S. Provisional Application No. 62/607,589, which was filed on Dec. 19, 2017. The contents of U.S. Provisional Application No. 62/607,589 are incorporated herein by reference in their entirety.

The present disclosure is directed to bottle closure assemblies which are made at least in part with a high density unimodal polyethylene. The bottle closure assembly includes a cap portion, a tether portion and a retaining means portion.

The manufacture of simple one-piece closures using polyethylene compositions is well known to persons skilled in the art.

Bottle closure systems and designs incorporating an integrated tethering means, which secures a cap portion to a bottle after the cap portion has been removed from a bottle opening are also well known. Such designs typically involve molding processes which present a more complicated and longer flow path for a chosen plastic material relative to simple one-piece closure designs. As such, it would be beneficial to make tethered closure systems using a thermoplastic material which shows good performance in molding applications, especially those which involve longer and more tortuous flow paths in a mold. It would also be advantageous, in some instances, to make a tethered closure system using a material that has sufficient stress crack resistance and flexibility. In these embodiments the tethering portion would be both strong enough to prevent loss of the cap portion once it has been removed from a bottle opening, and flexible enough to allow the tethering portion to be formed or bent into suitable closure system designs.

The present disclosure concerns bottle closure assemblies that include a cap portion, a tether portion and a retaining means portion, where the bottle closure assembly is made at least in part from a high density unimodal polyethylene.

An embodiment of the present disclosure provides a bottle closure assembly which includes a cap portion, a tether portion and a retaining means portion, the bottle closure assembly being made at least in part from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an embodiment of a bottle closure assembly fitted to a bottle opening and in a “closed” or “sealed” position. FIG. 1B shows an embodiment of a bottle closure assembly as a cap portion is rotated in order to bring about its removal from a bottle opening. FIG. 1C shows an embodiment of a bottle closure assembly after a cap portion has been removed from a bottle opening. FIG. 1C shows how an elongated tether portion connects at least one point on a cap portion to at least one point on a retaining collar portion once a cap portion has been removed from a bottle opening.

FIG. 2A shows an embodiment of a bottle closure assembly fitted over a bottle opening and before a cap portion has been removed from a bottle. FIG. 2B shows an embodiment of a bottle closure assembly after a cap portion has been removed from a bottle opening. FIG. 2B also shows how an elongated tether portion connects at least one point on a cap portion to at least one point on a retaining collar portion once a cap portion has been removed from a bottle opening, thereby preventing its loss.

FIG. 3A shows an embodiment of a bottle closure assembly. FIG. 3B shows an embodiment of a bottle closure assembly after a cap portion has been removed from a bottle opening. FIG. 3B also shows how an elongated tether portion connects at least one point on a cap portion to at least one point on a retaining collar portion once a cap portion has been removed from a bottle opening, thereby preventing its loss. FIG. 3C shows how an elongated tether portion connects at least one point on a cap portion to at least one point on a retaining collar portion once a cap portion has been removed from a bottle opening. FIG. 3C further shows that a bottle can be a carton, a container, or any other suitable containment vessel which has or is fitted with an aperture or opening which can be covered or sealed using a bottle closure assembly.

FIG. 4A shows an embodiment of a bottle closure assembly in the absence of a bottle. The bottle closure assembly has a cap portion, an elongated tether portion and a retaining collar portion. FIG. 4B shows an embodiment of a bottle closure assembly fitted over a bottle opening and before a cap portion has been removed from a bottle opening. FIG. 4C shows an embodiment of a bottle closure assembly after a cap portion has been removed from a bottle opening.

FIG. 5A shows an embodiment of a bottle closure assembly in the absence of a bottle. FIG. 5B shows an embodiment of a bottle closure assembly as a cap portion is rotated in order to bring about its removal from a bottle opening.

FIG. 6A shows an embodiment of a bottle closure assembly which fits over a bottle opening. FIG. 6B show an embodiment of a bottle closure assembly after a cap portion has been removed from a bottle opening. FIG. 6B shows how an elongated tether portion connects at least one point on a cap portion to at least one point on a retaining collar portion once a cap portion has been removed from a bottle opening.

FIG. 7A shows an embodiment of a bottle closure assembly fitted to a bottle opening and in a “closed” or “sealed” position. FIG. 7B shows an embodiment of a bottle closure assembly after a cap portion has been removed from a bottle opening. FIG. 7B shows how an elongated tether portion connects at least one point on a cap portion to at least one point on a retaining collar portion once a cap portion has been removed from a bottle opening.

FIG. 8-12. FIGS. 8 through 12 show a gel permeation chromatograph for the high density polyethylene of Examples 1 through 5 respectively.

FIG. 13A shows a perspective view of a closure having a tether proxy. FIG. 13B shows a front elevation view of a closure having a tether proxy. In FIGS. 13A and 13B a tether proxy connects a cap portion to a tamper evident band.

FIG. 14A shows a perspective view of a closure having a tether proxy after much of the tamper evident band has been removed. In FIG. 14A a tether proxy connects a cap portion to the remaining section of the tamper evident band.

FIG. 14B shows a front elevation partial cross-sectional schematic view of a closure having a tether proxy and being mounted on a pre-form for shear deformation testing. Prior to mounting the closure on the pre-form, much of the tamper evident band was removed. The tether proxy connects a cap portion to the remaining section of the tamper evident band. To measure shear deformation of the tether proxy, the remaining section of the tamper evident band is clamped in a stationary position to the pre-form, while the cap portion is rotated within a torque tester, as shown.

FIG. 14C shows a side elevation partial cross-sectional schematic view of a closure having a tether proxy and being mounted on a pre-form for tear deformation testing. The tamper evident band was deflected down and away from the cap portion, while leaving the tether proxy intact. The tether proxy connects the cap portion to the downwardly deflected tamper evident band. To measure tear deformation of the tether proxy, the downwardly deflected tamper evident band is clamped in a stationary position to the pre-form, while the cap portion is rotated within a torque tester, as shown.

FIGS. 15A and 15B show a perspective view and a front elevation view respectively, of a tether proxy after much of the cap portion and much of the tamper evident band have been removed. To measure tensile deformation of the tether proxy, the remaining section of the cap portion and the remaining section of the tamper evident band are each clamped and then drawn apart in a vertical direction, within a tensile tester, as shown.

Any suitable bottle closure assembly design including a cap portion or a closure portion, a tether portion and a retaining means portion is contemplated for use in the present disclosure, so long as it is made at least in part using a high density polyethylene as described herein. Some specific non-limiting examples of suitable bottle closure assemblies for use in the present disclosure are disclosed in U.S. Pat. Nos. 3,904,062; 4,474,302; 4,557,393; 4,564,114; 4,573,602; 4,583,652; 4,805,792; 5,725,115; 8,443,994; 8,720,716; 9,493,283; and 9,776,779; U.S. Pat. Pub. Nos 2004/0016715 and 2008/0197135; U.S. Design Pat. No. D593,856; and WO 2015/061834; all of which are incorporated herein by reference. For further reference, some bottle closure assembly designs which may be used in embodiments of the present disclosure are shown in FIGS. 1-7.

An embodiment of the disclosure is a bottle closure assembly including: a cap portion, a tether portion, and a retaining means portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and where the tether portion connects at least one point on the cap portion to at least one point on the retaining means portion, wherein the cap portion, optionally the tether portion, and optionally the retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including: a cap portion, an elongated tether portion, and a retaining means portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the elongated tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion, wherein the cap portion, optionally the elongated tether portion, and optionally the retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including an integrally molded: cap portion, tether portion, and retaining means portion; the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion; wherein the integrally molded: cap portion, tether portion and retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including an integrally molded: cap portion, elongated tether portion, and retaining means portion; the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the elongated tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion; wherein the integrally molded: cap portion, elongated tether portion and retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including an integrally molded: cap portion, elongated tether portion, and retaining collar portion; the cap portion being molded to reversibly engage and cover a bottle opening, the retaining collar portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the elongated tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining collar portion; wherein the integrally molded: cap portion, elongated tether portion and retaining collar portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including: a cap portion, an elongated tether portion, and a retaining collar portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining collar portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, the elongated tether portion including a tether strip which is frangibly connected along a portion of its upper edge to a descending annular edge of the cap portion and which is frangibly connected along a portion of its lower edge to an upper annular edge of the retaining collar portion, the tether strip being integrally formed with and connected at one end to at least one point on the cap portion and integrally formed with and connected at another end to at least one point on the retaining collar portion, the frangible sections being breakable when the cap portion is removed from a bottle opening, but where the cap portion remains connected to the retaining collar portion via the tether strip; wherein the cap portion, the elongated tether portion and the retaining collar portion are integrally molded from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including: a cap portion, an elongated tether portion, and a retaining collar portion, the cap portion being molded to reversibly engage and cover a bottle opening, the elongated tether portion including a tether strip which is frangibly connected along a portion of its upper edge to a descending annular edge of the cap portion and which is frangibly connected along a portion of its lower edge to an upper annular edge of the retaining collar portion, the tether strip being integrally formed with and connected at one end to at least one point on the cap portion and integrally formed with and connected at another end to at least one point on the retaining collar portion, the frangible sections being breakable when the cap portion is removed from a bottle opening, but where the cap portion remains connected to the retaining collar via the tether strip; wherein the cap portion, the elongated tether portion and the retaining collar portion are integrally molded from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

An embodiment of the disclosure is a bottle closure assembly including: a cap portion, a tether portion, and a retaining means portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and where the tether portion connects at least one point on the cap portion to at least one point on the retaining means portion, wherein the cap portion, optionally the tether portion, and optionally the retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 15 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

When integrally molded the bottle closure assembly presents long flow paths for a plastic material to fill during manufacturing. In the present disclosure, the term “integrally molded” means that that components referred to are molded in a single continuous mold.

In some embodiments, the cap portion is molded to reversibly engage and cover a bottle opening or aperture from which a liquid or other type of foodstuffs can be dispensed and so is removable therefrom.

In some embodiments, the retaining means portion, which, in some embodiments, may be a retaining collar portion, is generally not to be removed, or is not easily removable from a bottle and in some embodiments of the disclosure, the retaining collar engages a bottle neck, or an upper portion of a bottle.

In some embodiments, the tether portion, which, in some embodiments, may be an elongated tether portion, connects at least one point of the cap portion to at least one point on the retaining means portion, so that when the cap portion is removed from a bottle opening, the cap portion remains flexibly fixed to the bottle via the tether portion and the retaining means portion.

In the present disclosure, the terms “bottle”, “container”, “jar”, “carton”, “pouch”, “package” and the like may be used interchangeably in the present disclosure. That is, a “bottle closure assembly” may also be considered a “container closure assembly”, a “jar close assembly”, a “carton closure assembly”, a “pouch closure assembly”, a “package closure assembly” and the like. A person skilled in the art will understand that a “bottle closure assembly” as described in the present disclosure can be used to close or seal a number of different types of structural containers having different designs and contours.

The terms “cap”, “closure”, “closure portion”, “cap portion” and the like, are used in the present disclosure to connote any suitably shaped molded article for enclosing, sealing, closing or covering etc., a suitably shaped opening, a suitably molded aperture, an open necked structure or the like used in combination with a container, a bottle, a jar and the like.

In an embodiment of the disclosure the retaining means portion can reversibly or irreversible engage a bottle neck, a shoulder section of a bottle, or an upper portion of a bottle, or a fitment (e.g. a fitment on a pouch or a carton).

In an embodiment of the disclosure, the retaining means portion can also serve as a tamper evident band (TEB).

In the present disclosure, the term “bottle neck” should be construed to mean a bottle neck per se but also any sort of similar or functionally equivalent structure such as a spout, a spigot, a fitment, or the like.

In an embodiment of the disclosure the retaining means portion is molded or shaped to reversibly or irreversible engage a bottle neck, a shoulder section of a bottle, or an upper portion of a bottle.

In an embodiment of the disclosure the retaining means portion is a retaining collar portion which reversibly or irreversibly engages a bottle neck, a shoulder section of a bottle, or an upper portion of a bottle.

In an embodiment of the disclosure the retaining collar portion is circularly or annularly shaped so as to reversibly or irreversibly engage a bottle neck, a shoulder section of a bottle, or an upper portion of a bottle.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, a tether portion and a retaining means portion where the cap portion, the tether portion and the retaining means portion are all integrally molded in one piece.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, a tether portion and a retaining collar portion where the cap portion, the tether portion and the retaining collar portion are all integrally molded in one piece.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, an elongated tether portion and a retaining means portion where the cap portion, the elongated tether portion and the retaining means portion are all integrally molded in one piece.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, an elongated tether portion and a retaining collar portion where the cap portion, the elongated tether portion and the retaining collar portion are all integrally molded in one piece.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, a tether portion and a retaining means portion where the cap portion, the tether portion and the retaining means portion are separately molded.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, a tether portion and a retaining collar portion where the cap portion, the tether portion and the retaining collar portion are separately molded.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, an elongated tether portion and a retaining means portion where the cap portion, the elongated tether portion and the retaining means portion are separately molded.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, an elongated tether portion and a retaining collar portion where the cap portion, the elongated tether portion and the retaining collar portion are separately molded.

In embodiments of the disclosure, when separately molded the cap portion, the tether portion and the retaining means portion may be fixed together using any means known in the art. For example, the cap portion, the tether portion and the retaining means portion may be glued together, or welded together using applied heat, sonication or other methods known in the art for fusing plastic materials together.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, a tether portion and a retaining means portion where the cap portion, the tether portion and the retaining means portion are made from the same or different materials.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, a tether portion and a retaining collar portion where the cap portion, the tether portion and the retaining collar portion are made from the same or different materials.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, an elongated tether portion and a retaining means portion where the cap portion, the elongated tether portion and the retaining means portion are made from the same or different materials.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion, an elongated tether portion and a retaining collar portion where the cap portion, the elongated tether portion and the retaining collar portion are made from the same or different materials.

In an embodiment of the present disclosure, the “tether portion” is of sufficient length and/or has a design which allows removal of a “cap portion” from a bottle opening while at the same time preventing the loss of the cap portion by maintaining a connection between the cap portion and a bottle, container or the like by forming a connection between at least one point on the cap portion and at least one point on a “retaining means portion”.

In an embodiment of the present disclosure the tether portion may be an “elongated tether portion”, where “elongated” means that the tether portion will have at least one dimension (length) which is larger than at least one other dimension (width or height/thickness) or vice versa. Or considered another way, “elongated” means that the tether has a length which is greater than its width and/or height/thickness.

In an embodiment of the present disclosure the tether portion will have dimensions (e.g. width and/or height/thickness) which offer sufficient strength to prevent facile cleavage or breakage of the tether when placed under stress or duress, such as for example when the tether is subjected to bending or flexional forces. For example, in an embodiment of the disclosure, the tether will have sufficient width and/or height/thickness so as to prevent facile breakage of the tether when masticated.

In an embodiment of the present disclosure, the “elongated tether portion” is of sufficient length and/or has a design which allows removal of a “cap portion” from a bottle opening while at the same time preventing the loss of the cap portion by maintaining a connection between the cap portion and a bottle, container or the like by forming a connection between at least one point on the cap portion and at least one point on a “retaining means portion”.

In embodiments of the disclosure, the retaining means portion may be a “retaining collar portion” which engages some portion of a bottle neck or an upper portion of a bottle, container or the like.

In embodiments of the disclosure, the retaining means portion may be a “retaining collar portion” which irreversibly engages some portion of a bottle neck, a spout, a spigot, a fitment on a pouch, or the like.

Alternatively, the retaining means portion may be a “retaining collar portion” which engages a bottle neck, or an upper portion of a bottle, container or the like.

In an embodiment of the disclosure, the retaining collar portion may rotatably engage a bottle neck, or upper portion of a bottle, container or the like.

In an embodiment of the disclosure, the retaining means portion is a retaining collar portion which is molded to irreversibly engage a bottle neck or an upper portion of a bottle, container or the like.

In an embodiment of the disclosure, the retaining collar portion is annularly shaped or circularly shaped and can fit over and engage a bottle neck or an upper portion of a bottle, container or the like.

The cap portion may be a single contiguous piece, or it may itself comprise one or more cap portion structures.

The tether portion in the present disclosure need not serve as a hinged connection between a cap portion and a retaining means portion (such as for example a retaining collar portion), and the tether portion need not comprise a hinged portion or area, but the tether portion may in some embodiments of the disclosure comprise a hinge and when present the hinge may be a so called “living hinge”.

In an embodiment of the disclosure the elongated tether portion has a length which is sufficient to allow the cap portion of the bottle closure assembly to swing or hang out of the way of a bottle opening, aperture or the like so as not to interfere with the dispensation of the bottle contents, while at the same time tethering the cap portion to a bottle via the retaining means portion.

The cap portion may itself be a screw cap which threadingly engages a threaded system on a bottle neck, spigot, spout, valve, fitment on a pouch, or the like. The cap portion may alternatively be a snap cap which reversibly engages a bottle neck, spigot, spout or the like. The cap portion may also reversibly engage a retaining collar portion in a snap fitting or in a complementary arrangement of threaded structures. The cap portion may comprise a first cap portion and a second cap portion, where the first cap portion engages the second cap portion in a snap fitting, and the second cap portion engages a bottle neck, or upper portion of a bottle in a reversible or irreversible manner. For example a second cap portion may have a threaded structure which threadingly engages a threaded system on a bottle neck. Alternatively, the second cap portion may itself engage a bottle neck by any suitable type of snap fitting. The cap portion may also comprise more than two cap portions.

In an embodiment of the disclosure, the bottle closure assembly includes a cap portion adapted to close an opening in a bottle or the like by making a frictional engagement with the opening.

In an embodiment of the disclosure, the cap portion has internal threads which mate with external threads surrounding an opening in a bottle, such as on a bottle neck, spigot, or spout for example.

In an embodiment of the disclosure, the retaining collar portion is adapted to cooperate with a shoulder or a flange on the neck of a bottle or an upper portion of a bottle which is to be sealed by the cap portion.

In an embodiment of the disclosure, the retaining collar portion is annularly or cylindrically shaped and fits onto the neck of a bottle and is coupled to the same, using any suitable coupling means, such as a snap fitting, or a threaded engagement. In an embodiment, the retaining collar portion is molded to snap fit onto a bottle neck, bottle aperture, spigot, spout or the like. In an embodiment, the retaining collar portion may be threaded onto a bottle neck, bottle aperture, spigot, spout or the like. In an embodiment the retaining collar portion may itself have an internal threading system which mates with external threads on a bottle neck, bottle aperture, spigot, spout or the like. In an embodiment, the retaining collar portion is dimensioned to be engaged beneath a flange or shoulder molded into a bottle neck or an upper portion of a bottle. For example, the retaining collar portion may have an annular radial dimension which prevents it from moving past an annular shoulder integrally molded into a bottle neck or into an upper portion of a bottle. In this case the annular outwardly extending shoulder on a bottle neck or on an upper portion of a bottle acts as a camming surface which prevents movement of the retaining collar toward a bottle opening. Such a shoulder on a bottle could for example have a tapered outer annular edge which allows the retaining collar portion to be slipped onto the bottle in an irreversible manner. In an embodiment of the disclosure, there may be outwardly extending annularly spaced bosses or the like on a bottle neck or an upper portion of a bottle, against which the retaining collar abuts to hold it on to a bottle neck, bottle aperture, spigot, spout or the like. Persons skilled in the art will appreciate that other means could be used to secure the retaining collar portion to a bottle neck, the upper portion of a bottle, a spout, spigot and the like.

In an embodiment of the disclosure, the elongated tether portion includes a connecting strip having a first end connected to a least one point of the cap portion and a second end connected to at least one point of the retaining collar portion, a lower edge and an upper edge, wherein when the cap portion is fitted on to a bottle opening, the connecting strip at least partially encircles a bottle neck, spout, or the like between the cap portion and the retaining collar portion, and where at least a portion of the upper edge of the connecting strip is frangibly connected to a lower edge of the cap portion, and where at least a portion of the lower edge of the connecting strip is frangibly connected to an upper edge of the retaining collar portion, and where when the cap portion is removed from a bottle opening by breaking the frangible connections between the cap portion, the connecting strip and the retaining collar portion, the cap portion remains secured to retaining collar portion and the bottle via the connecting strip.

In an embodiment the elongated tether portion is a cylindrically adapted connecting strip which at least partially encircles a bottle neck, spout, or the like and is located between the cap portion and the retaining collar portion prior to removal of the cap portion form a bottle opening.

In an embodiment the elongated tether portion has a first end which is connected to at least one point on the cap portion and a second end which is connected to at least one point on the retaining collar portion.

In an embodiment, the cap portion, the elongated tether portion and the retaining collar portion are integrally molded so that the elongated tether portion has a first end which is connected to at least one point on the cap portion and a second end which is connected to at least one point on the retaining collar.

In an embodiment, the cap portion, the elongated tether portion and the retaining collar portion are integrally molded so that the elongated tether portion has a first end which is connected to at least one point on the cap portion and a second end which is connected to at least one point on the retaining collar portion, and wherein the elongated tether portion has an upper edge and a lower edge, where at least a portion of the upper edge is frangibly connected to a lower edge of the cap portion, and at least a portion of the lower edge is frangibly connected to an upper edge of the retaining collar portion, the frangibly connected portions being breakable when the closure is removed from a bottle opening.

In an embodiment of the disclosure, the frangible connections or frangibly connected portions are regularly or irregularly spaced molded sections (e.g. pins) having a dimension suitably small to allow facile breakage.

Frangible connections or frangibly connected portions can also be thought of as defining a weakening line along which the elongated tethering portion can be separated from the cap portion and the retaining collar portion. Such weakening lines can be generally defined as open sections alternating with bridging sections, where the bridging sections have a dimension suitably small to allow facile breakage. Alternatively, the weakening lines are defined by lines of plastic which have been made thin enough to break under stress.

In an embodiment of the disclosure, a single piece of a molded plastic having a suitable shape, is purposely weakened (by for example, regular or irregularly spaced cuts) along predetermined lines to define a cap portion, an elongated tether portion and a retaining collar portion, wherein the cap portion is shaped to reversibly engage and cover a bottle opening, the retaining means portion is shaped to irreversibly engage a bottle neck or an upper portion of a bottle, and where the elongated tether portion connects at least one point on the cap portion to at least one point on the retaining means portion.

In an embodiment of the disclosure, the bottle closure assembly includes an upper cap portion, an intermediate elongate tethering portion, and a lower retaining collar portion, where the intermediate elongate tethering portion has a first end permanently connected to at least one point of the upper cap portion and a second end permanently connected to at least one point on the lower retaining collar portion, wherein the intermediate elongate tethering portion is'partially joined to a lower annular edge of the upper cap portion along a first peripheral weakening line and the intermediate elongate tethering portion is partially joined to an upper annular edge of the lower retaining collar portion along a second peripheral weakening line, wherein removal of the upper cap portion from a bottle separates the upper cap portion from the intermediate elongate tethering portion along the first peripheral weakening line and separates the lower retaining collar portion from the intermediate elongate tethering portion along the second weakening line, while maintaining a linkage between the upper cap portion and the lower retaining collar portion through the intermediate elongate tethering portion.

In an embodiment of the disclosure, and with reference to FIGS. 1A-1C, the bottle closure assembly includes: an upper cap portion, 1 dimensioned to reversibly cover and close a bottle opening, a lower retaining collar portion, 10 dimensioned to irreversibly engage a bottle neck, or an upper portion of a bottle, and an elongated tether portion, 5 being dimensioned as a strip which at least partially encircles a bottle neck between the upper cap portion and the lower retaining collar portion, the strip including a first end, a second end, an upper edge and a lower edge, the upper edge of which is in part contiguous with the upper cap portion, the lower edge of which is in part contiguous with the lower retaining collar portion, whereby removal of the upper cap portion from a bottle (by for example rotation about a threaded system on the bottle neck) separates the elongated tether portion from the upper cap portion and the lower retaining collar portion, while at the same time leaving the upper cap portion attached to the lower retaining collar via the elongated tether portion.

In an embodiment of the disclosure, and with reference to FIGS. 2A and 2B, the bottle closure assembly includes: an upper cap portion, 1 dimensioned to reversibly cover and close a bottle opening, 2 a lower retaining collar portion, 10 dimensioned to irreversibly engage a bottle neck, 3 or an upper portion of a bottle, and an elongated tether portion, 5 being dimensioned as a strip which at least partially encircles a bottle neck between the upper cap portion and the lower retaining collar portion, the strip including a first end, 6 a second end, 7 an upper edge, 11 and a lower edge, 12, the upper edge of which is in part frangibly attached, 8 to the upper cap portion, and in part contiguous with the upper cap portion, the lower edge of which is in part frangibly attached, 9 to the lower retaining collar portion and in part contiguous with the lower retaining collar portion, whereby removal of the upper cap portion from a bottle will rupture the frangible attachments while leaving the upper cap portion attached to the lower retaining collar portion via the elongated tether portion. In an embodiment and with reference to FIG. 2B, the bottle opening may have peripheral threads, 15 which engage threads on the inside of the cap portion.

In an embodiment of the disclosure, and with reference to FIGS. 3A-3C, the bottle closure assembly includes: an upper cap portion, 1 dimensioned to reversibly cover and close a bottle opening, a lower retaining collar portion, 10 dimensioned to irreversibly engage a bottle neck, 3 or an upper portion of a bottle, and an elongated tether portion, 5 being dimensioned as a strip which at least partially encircles a bottle neck between the upper cap portion and the lower retaining collar portion, the strip having a first end, 6 a second end, 7 an upper edge, and a lower edge, the upper edge of which is in part frangibly attached to the upper cap portion by frangible elements, 20 (such as for example breakable pins), and in part contiguous with the upper cap portion, the lower edge of which is in part frangibly attached to the lower retaining collar portion by frangible elements, 20 (such as for example breakable pins) and in part contiguous with the lower retaining collar portion, whereby removal of the upper cap portion from a bottle opening will rupture the frangible attachments while leaving the upper cap portion attached to the lower retaining collar portion via the elongated tether portion, 5. In an embodiment and with reference to FIG. 3B, the bottle neck and opening may have peripheral threads, 15 which engage threads on the inside of the cap portion.

In an embodiment of the disclosure, and with reference to FIGS. 4A-4C, the bottle closure assembly includes a cap portion, 1, an elongated tether portion, 5, and a retaining collar portion, 10.

In an embodiment of the disclosure, and with reference to FIGS. 5A and 5B, the bottle closure assembly includes: a cap portion, 1 a tether portion, 5 and a retaining means portion, 10 the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, 18 and the tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion, the cap portion and the retaining collar portion extending coaxially with each other, the tether portion including a tabbed tether strip which is integrally formed with and secured at its respective ends (6 and 7) to the cap portion and the retaining collar portion, the tether strip being joined to the cap portion and the retaining collar along a preselected length of the tether strip to be manually separated from the cap portion and the retaining collar portion by frangible elements, 20 of a preselected thickness to permit the elongated tether strip to be manually separated from the cap portion and the retaining collar portion along the pre-selected length, the tether strip being of such length so as to permit the cap portion to be removed from a bottle opening while at the same remaining attached to the bottle via the tether strip and the retaining collar. In an embodiment and as shown in FIG. 5B, a cap portion may have a circular top wall, 16 and a descending annular side wall 17.

In an embodiment of the disclosure the bottle closure assembly includes: a cap portion having a top wall and a side wall, an elongated tether portion, and a retaining collar portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining collar portion being annular and being molded to irreversibly engage a ridge or flange on a bottle neck or on an upper portion of a bottle, and the elongated tether portion being integrally molded with the cap portion and the retaining collar portion to connect at least one point on the cap side wall to at least one point on the retaining collar portion, wherein the elongated tether portion runs between the cap side wall and the retaining collar portion along the circumference of the cap portion when the cap portion is on a bottle and the elongated tether portion connects at least one point on the cap side wall to at least one point on the retaining collar portion when the cap portion is removed from a bottle.

In an embodiment of the disclosure, and with reference to FIGS. 6A and 6B, the bottle closure assembly includes an upper cap portion, 1 an intermediate elongate tethering portion, 5 and a lower retaining collar portion, 10 where the intermediate elongate tethering portion has a first end permanently connected to at least one point of the upper cap portion and a second end permanently connected to at least one point on the lower retaining collar portion, wherein the intermediate elongate tethering portion is partially joined to a lower annular edge of the upper cap portion along a first peripheral weakening line defined by perforations, 25 and the intermediate elongate tethering portion is partially joined to an upper annular edge of said lower retaining collar portion along a second peripheral weakening line defined by perforations, 25 wherein removal of the upper cap portion from a bottle separates the upper cap portion from the tethering portion along the first peripheral weakening line and separates the lower retaining collar portion from the tethering portion along the second weakening line, while maintaining a linkage between the upper cap portion and the lower retaining collar portion through the intermediate elongated tethering portion.

In an embodiment of the disclosure and with reference to FIGS. 6A and 6B, a bottle neck 3, may have an annular groove 28, which presents a flange onto which the cap portion, 1 may reversibly engage in a snap fit arrangement. In an embodiment and with reference to FIGS. 6A and 6B a bottle neck may have an outwardly extended annular flange, 29 which prevents a retaining collar portion, 10 from being removed from a bottle neck.

In an embodiment of the disclosure, and with reference to FIGS. 7A and 7B, the bottle closure assembly includes a cap portion, 1, an elongated tether portion, 5, and a retaining collar portion, 10. The elongated tether portion connects at least one point of the cap portion at a first end, 6 to at least one point of the retaining collar portion at a second end, 7. The elongated tether portion may be further joined to the cap portion along a frangible connection 8. The elongated tether portion may be further joined to the retaining collar portion along a frangible connection 9. Separation of the cap portion from the elongated tether portion along a frangible connection 8 along with separation of the retaining collar portion from the elongated tether portion along a frangible connection 9, allows removal of the cap portion from a bottle opening while at the same time securing it to the bottle via the elongated tether portion and the retaining collar portion.

In an embodiment of the disclosure, the bottle closure assembly includes: a cap portion, the cap portion being dimensioned to cover and close a bottle opening, a retaining collar portion, and an elongated tether portion which forms an elastic connection between at least one point on the cap portion and at least one point on the retaining collar portion.

In an embodiment of the disclosure, the retaining means portion is integrally molded into a bottle, container or the like.

In an embodiment of the disclosure, the retaining collar portion is integrally molded into a bottle, container or the like.

In an embodiment of the disclosure, the tether portion fixes the cap portion to the retaining collar portion which remains secured to the bottle, making it difficult to separate the cap portion from the bottle, thereby preventing its loss, while at the same time allowing rotation of the cap portion for facile removal and replacement of the same from and onto a bottle opening.

In an embodiment of the present disclosure, the bottle closure assembly is made in part or in full using a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the disclosure the cap portion, optionally the tether portion, and optionally the retaining collar portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the disclosure, the cap portion, the tether portion, and the retaining collar portion are all integrally molded from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the present disclosure, the bottle closure assembly is made in part or in full using a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 30 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the disclosure the cap portion, optionally the tether portion, and optionally the retaining collar portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 30 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the disclosure, the cap portion, the tether portion, and the retaining collar portion are all integrally molded from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 30 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the present disclosure, the bottle closure assembly is made in part or in full using a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 15 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the disclosure the cap portion, optionally the tether portion, and optionally the retaining collar portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 15 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

In an embodiment of the disclosure, the cap portion, the tether portion, and the retaining collar portion are all integrally molded from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 15 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.

Suitable high density unimodal polyethylene for use in the manufacture of part or all of the bottle closure assembly are described in more detail below.

In an embodiment of the present disclosure, the high density polyethylene is not a polymer blend. The phrase “polymer blend” as used in the present disclosure means a polyethylene composition which is comprised of at least two major different polymer composition components (by “major” it is meant that each of the different polymers comprise at least 5 or more weight percent of the total weight of the polymer blend). That is, in an embodiment of the disclosure, the high density polyethylene is neither the result of in situ reactor blending of different polymers (including those made with multiple catalysts and/or different reactors operating under different conditions) or dry blending or melt blending methods.

In an embodiment of the present disclosure, the high density polyethylene has a density from 0.940 to 0.967 g/cm³. In further embodiments of the present disclosure, the high density polyethylene has a density of from 0.940 to 0.965 g/cm³, or from 0.949 to 0.963 g/cm³.

In an embodiment of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of less than about 35 g/10 min.

In an embodiment of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of less than about 30 g/10 min. In further embodiments of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of less than about 28 g/10 min, or less than about 26 g/10 min, or less than about 24 g/10 min, or less than about 22 g/10 min, or less than about 20 g/10 min, or less than about 18 g/10 min, or less than about 15 g/10 min, or less than about 10 g/10 min.

In an embodiment of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of from 0.5 to less than 10.0 g/10 min. In further embodiments of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of from 0.5 to 9.5 g/10 min, or from 1.0 to 9.0 g/10 min, or from 2.5 to 7.5 g/10 min, or from 2.0 to 9.5 g/10 min, or from 2.5 to 9.5 g/10 min.

In an embodiment of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of at least 10.0 g/10 min.

In an embodiment of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of from 10.0 to 30.0 g/10 min. In further embodiments of the disclosure, the high density polyethylene has a melt index, I₂ as determined according to ASTM D1238 (2.16 kg/190° C.) of from greater than 10.0 to 28.0 g/10 min, or from greater than 10.0 to 26.0 g/10 min, or from greater than 10.0 to 24.0 g/10 min, or from greater than 10.0 to 22.0 g/10 min, or from greater than 10.0 to 20.0 g/10 min, or from greater than 10.0 to 19.5 g/10 min, or from 10.0 to 28.0 g/10 min, or from 10.0 to 26.0 g/10 min, or from 10.0 to 24.0 g/10 min, or from 10.0 to 22.0 g/10 min, or from 10.0 to 20.0 g/10 min, or from 10.0 to 19.5 g/10 min.

In an embodiment of the disclosure, the high density polyethylene has a melt flow ratio (MFR) defined by I₂₁/I₂ of less than about 40. In further embodiments of the disclosure, the high density polyethylene has a melt flow ratio, I₂₁/I₂ of less than about 30, or from about 15 to about 30, or from about 20 to about 30.

In an embodiment of the present disclosure, the high density polyethylene has a unimodal profile in a gel permeation chromatograph obtained according to the method of ASTM D6474-99. The term “unimodal” is herein defined to mean there will be only one significant peak or maximum evident in the GPC-curve. A unimodal profile includes a broad unimodal profile. Alternatively, the term “unimodal” connotes the presence of a single maxima in a molecular weight distribution curve generated according to the method of ASTM D6474-99. In contrast, by the term “bimodal” it is meant that there will be a secondary peak or shoulder evident in a GPC-curve which represents a higher or lower molecular weight component (i.e. the molecular weight distribution, can be said to have two maxima in a molecular weight distribution curve). Alternatively, the term “bimodal” connotes the presence of two maxima including peaks and/or shoulders in a molecular weight distribution curve generated according to the method of ASTM D6474-99. The term “multi-modal” denotes the presence of two or more maxima including peaks and/or shoulders in a molecular weight distribution curve generated according to the method of ASTM D6474-99.

In an embodiment of the present disclosure, the high density polyethylene has an environmental stress cracking resistance (ESCR) Condition B (10% IGEPAL) of at least 1 hour.

In an embodiment of the present disclosure, the high density polyethylene has an ESCR Condition B (10% IGEPAL) of from 1 to 10 hours.

IGEPAL® CO-630 is a polyoxyethylene (9) nonylphenylether available from SIGMA-ALDRICH® which has a M_(n) of 617 the structure below.

In an embodiment of the disclosure, the high density polyethylene has a weight average molecular weight (Mw) from about 20,000 to about 100,000. In other embodiments of the disclosure the high density polyethylene has a weight average molecular weight (Mw) from about 25,000, to about 85,000, or from about 30,000 to about 85,000, or from about 35,000 to about 80,000, or from about 40,000 to about 80,000, or from about 40,000 to about 75,000, or from about 45,000 to about 80,000, or from 50,000 to 75,000, or from 55,000 to 75,000.

In an embodiment of the disclosure, the high density polyethylene has a molecular weight distribution (M_(w)/M_(n)) of less than about 5.0. In further embodiments of the disclosure, the high density polyethylene has a molecular weight distribution (M_(w)/M_(n)) of less than about 4.5, or less than about 4.0, or less than about 4.0, or less than about 3.5, or less than about 3.0, or from about 2.0 to about 5.0, or from about 2.0 to about 4.5, or from about 2.0 to about 4.0, or from about 2.0 to about 3.5, or from about 2.5 to about 4.0, or from about 2.5 to about 3.5.

In an embodiment of the disclosure, the high density polyethylene has a z-average molecular weight (Mz) from about 75,000 to about 450,000. In other embodiments of the disclosure the high density polyethylene has a weight average molecular weight (M_(Z)) from about 100,000, to about 400,000, or from about 100,000 to about 350,000, or from about 75,000 to about 300,000, or from about 75,000 to about 250,000, or from about 100,000 to about 250,000, or from about 75,000 to 225,000, or from about 75,000 to about 200,000, or from about 100,000 to about 225,000, or less than about 450,000, or less than about 400,000, or less than about 350,000, or less than about 300,000, or less than about 250,000, or less than about 200,000.

In an embodiment of the disclosure, the high density polyethylene has a Z-average molecular weight distribution (M_(Z)/M_(W)) of less than about 4.5. In further embodiments of the disclosure, the high density polyethylene has a z-average molecular weight distribution (M_(Z)/M_(W)) of less than about 4.0, or less than about 3.5, or less than about 3.0, or from about 2.0 to about 4.5, or from about 2.5 to about 4.0, or from about 2.0 to about 3.5.

In an embodiment of the disclosure, the high density polyethylene has an amount of terminal unsaturation of at least 0.35 per 1000 carbons (or per 1000 carbon atoms), or at least 0.40 per 1000 carbons, or at least 0.45 per 1000 carbons, or greater than 0.45 per 1000 carbons, or at least 0.50 per 1000 carbons, or greater than 0.50 per 1000 carbons, or at least 0.55 per 1000 carbons, or greater than 0.55 per thousand carbons, or at least 0.60 per 1000 carbons, or greater than 0.60 per 1000 carbons, or at least 0.65 per 1000 carbons, or greater than 0.65 per 1000 carbons, or at least 0.70 per 1000 carbons, or greater than 0.70 per 1000 carbons.

In an embodiment of the disclosure, the high density polyethylene has a total amount of unsaturation (which includes internal, side chain, and terminal unsaturation) of at least 0.40 per 1000 carbons (or per 1000 carbon atoms), or at least 0.45 per 1000 carbons, or at least 0.50 per 1000 carbons, or greater than 0.50 per 1000 carbons, or at least 0.55 per 1000 carbons, or greater than 0.55 per 1000 carbons, or at least 0.60 per 1000 carbons, or greater than 0.60 per thousand carbons, or at least 0.65 per 1000 carbons, or greater than 0.65 per 1000 carbons, or at least 0.70 per 1000 carbons, or greater than 0.70 per 1000 carbons, or at least 0.75 per 1000 carbons, or greater than 0.75 per 1000 carbons.

In an embodiment of the present disclosure, the high density polyethylene is an ethylene homopolymer.

As used herein, the term “homopolymer” is meant to convey its conventional meaning, that the polymer is prepared using only ethylene as a deliberately added polymerizable monomer.

In an embodiment of the present disclosure, the high density polyethylene is a polyethylene copolymer.

By the term “ethylene copolymer” or “polyethylene copolymer”, it is meant that the product polymer is the product of a polymerization process, where ethylene and one or more than one comonomer were deliberately added or was deliberately present as polymerizable olefins.

In an embodiment of the disclosure the high density polyethylene is a polyethylene copolymer of ethylene and one or more than one alpha olefin.

Suitable alpha olefin comonomers for polymerization with ethylene to make the high density polyethylene include 1-butene, 1-hexene and 1-octene.

Examples of polyethylene homopolymers which are useful as the high density polyethylene in the present disclosure are SCLAIR® 2908 and SCLAIR® 2907 which are commercially available from NOVA Chemicals Corporation. Examples of polyethylene copolymers which are useful as the high density polyethylene in the present disclosure are SCLAIR® 2710 and SCLAIR® 2807 which are commercially available from NOVA Chemicals Corporation.

In an embodiment of the disclosure the polyethylene copolymer includes from about 0.1 to about 5 weight %, in some cases less than about 3 weight %, in other instances less than about 1.5 weight % of an alpha olefin chosen from 1-butene, 1-hexene, 1-octene and mixtures thereof.

In an embodiment of the disclosure, the polyethylene copolymer includes polymerized ethylene and 1-butene.

In an embodiment of the disclosure, the polyethylene copolymer has a density of from about 0.945 to about 0.960 g/cm³ as determined according to ASTM D 792. In other embodiments of the disclosure the polyethylene copolymer has a density of from about 0.948 to about 0.958 g/cm³, or from about 0.949 g/cm³ to about 0.955 g/cm³.

Examples of polyethylene copolymers which are useful as the high density polyethylene in the present disclosure include by way of non-limiting example, SCLAIR® 2710, and SCLAIR® 2807, each of which is commercially available from NOVA Chemicals Corporation.

In an embodiment of the disclosure, the polyethylene homopolymer has a density from about 0.955 to about 0.967 g/cm³ as determined according to ASTM D 792. In other embodiments of the disclosure the polyethylene homopolymer has a density of from about 0.958 to about 0.965 g/cm³, or from about 0.958 to about 0.963 g/cm³, or from about 0.959 to 0.963 g/cm³.

Examples of polyethylene homopolymers which are useful as the high density polyethylene in the present disclosure include by way of non-limiting example, SCLAIR® 2907, and SCLAIR®2908, each of which is commercially available from NOVA Chemicals Corporation.

In an embodiment of the disclosure, the high density polyethylene suitable for use in the present disclosure may be prepared using conventional polymerization processes, non-limiting examples of which include gas phase, slurry and solution phase polymerization processes. Such processes are well known to those skilled in the art.

In an embodiment of the disclosure, the high density polyethylene may be prepared using conventional catalysts. Some non-limiting examples of conventional catalysts include chrome based catalysts and Ziegler-Natta catalysts. Such catalysts are well known to those skilled in the art.

Solution and slurry phase polymerization processes are generally conducted in the presence of an inert hydrocarbon solvent/diluent, such for example, a C₄₋₁₂ hydrocarbon which may be unsubstituted or substituted by a C₁₋₄ alkyl group, such as, butane, pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane or hydrogenated naphtha. A non-limiting example of a commercial solvent is Isopar E (C₈₋₁₂ aliphatic solvent, Exxon Chemical Co.). The monomers are dissolved in the solvent/diluent.

A slurry polymerization process may be conducted at temperatures of from about 20° C. to about 180° C., or from 80° C. to about 150° C., and the polyethylene composition being made is insoluble in the liquid hydrocarbon diluent.

A solution polymerization process may be conducted at temperatures of from about 180° C. to about 250° C., or from about 180° C. to about 230° C., and the polyethylene composition being made is soluble in the liquid hydrocarbon phase (e.g. the solvent).

A gas phase polymerization process can be carried out in either a fluidized bed or a stirred bed reactor. A gas phase polymerization typically involves a gaseous mixture including from about 0 to about 15 mole % of hydrogen, from about 0 to about 30 mole % of one or more C₃₋₈ alpha-olefins, from about 15 to about 100 mole % of ethylene, and from about 0 to about 75 mole % of an inert gas at a temperature from about 50° C. to about 120° C., or from about 75° C. to about 110° C.

Suitable alpha olefins which may be polymerized with ethylene in the case of a polyethylene copolymer are C₃₋₈ alpha olefins such as one or more of 1-butene, 1-hexene, and 1-octene.

In an embodiment of the disclosure the high density polyethylene is made in a solution phase polymerization reactor.

In an embodiment of the disclosure the high density polyethylene is prepared by contacting ethylene and optionally an alpha-olefin with a polymerization catalyst under solution polymerization conditions.

In an embodiment of the disclosure the high density polyethylene is made with a Ziegler-Natta polymerization catalyst.

In an embodiment of the disclosure the high density polyethylene is made in a single solution phase polymerization reactor.

In an embodiment of the disclosure, the high density polyethylene is made in a solution polymerization process using a Ziegler-Natta catalyst.

In an embodiment of the disclosure the high density polyethylene is made in a single solution phase polymerization reactor using a Ziegler-Natta catalyst.

The term “Ziegler-Natta” catalyst is well known to those skilled in the art and is used herein to convey its conventional meaning. Ziegler-Natta catalysts comprise at least one transition metal compound of a transition metal selected from groups 3, 4, or 5 of the Periodic Table (using IUPAC nomenclature) and an organoaluminum component that is defined by the formula:

AI(X′)_(a)(OR)_(b)(R)_(c)

wherein: X′ is a halide (for example chlorine); OR is an alkoxy or aryloxy group; R is a hydrocarbyl (for example an alkyl having from 1 to 10 carbon atoms); and a, b, or c are each 0, 1, 2, or 3 with the provisos, a+b+c=3 and b+c+c≥1. As will be appreciated by those skilled in the art of ethylene polymerization, conventional Ziegler-Natta catalysts may also incorporate additional components such as an electron donor. For example, an amine or a magnesium compound or a magnesium alkyl such as butyl ethyl magnesium and a halide source (which is typically a chloride such as tertiary butyl chloride). Such components, if employed, may be added to the other catalyst components prior to introduction to the reactor or may be added directly to the reactor. The Ziegler-Natta catalyst may also be “tempered” (i.e. heat treated) prior to being introduced to the reactor (again, using techniques which are well known to those skilled in the art and published in the literature).

In an embodiment of the disclosure, the high density polyethylene has less than 1.5 ppm, or less than 1.3 ppm, or ≤1.0 ppm, or ≤0.9 ppm, or ≤0.8, or less than 0.8 ppm, or ≤0.75 ppm, or less than 0.50 ppm of titanium (Ti) present.

In an embodiment of the disclosure, the high density polyethylene has less than 1.5 ppm, or less than 1.3 ppm, or ≤1.0 ppm, or ≤0.9 ppm, or ≤0.8 ppm, or ≤0.75, or ≤0.60 ppm of aluminum (Al) present.

In an embodiment of the disclosure, the high density polyethylene has less than 0.5 ppm, or less than 0.4 ppm, or ≤0.3 ppm, or ≤0.2 ppm, or 5. 0.15 ppm, or ≤0.1 ppm, of chlorine (Cl) present.

In an embodiment of the disclosure, the high density polyethylene has less than 4.0 ppm, or less than 3.0 ppm, or ≤2.5 ppm, or ≤2.0 ppm, of magnesium (Mg) present.

In an embodiment of the disclosure, the high density polyethylene has less than 0.4 ppm, or less than 0.3 ppm, or ≤0.25 ppm, or ≤0.20 ppm, of chromium (Cr) present.

In an embodiment of the disclosure the high density polyethylene includes one or more nucleating agents.

In an embodiment of the disclosure the high density polyethylene includes a nucleating agent or a mixture of nucleating agents.

The high density polyethylene may be compounded or dry-blended either by a manufacturer or a converter (e.g., the company converting the resin pellets into the final product). The compounded or dry-blended high density polyethylene may contain fillers, pigments and other additives. Typically, fillers are inert additives, such as, clay, talc, TiO₂ and calcium carbonate, which may be added to the high density polyethylene in amounts from about 0 weight % up to about 50 weight %, in some cases, less than 30 weight % of fillers are added. The compounded or dry-blended high density polyethylene may contain antioxidants, heat and light stabilizers, such as, combinations of one or more of hindered phenols, phosphates, phosphites and phosphonites, typically, in amounts of less than about 0.5 weight % based on the weight of the polyethylene compositions. Pigments may also be added to the high density polyethylene in small amounts. Non-limiting examples of pigments include carbon black, phthalocyanine blue, Congo red, titanium yellow, etc.

The high density polyethylene may contain a nucleating agent or a mixture of nucleating agents in amounts of from about 5 parts per million (ppm) to about 10,000 ppm based on the weight of the polyethylene polymer. The nucleating agent may be chosen from dibenzylidene sorbitol, di(p-methyl benzylidene) sorbitol, di(o-methyl benzylidene) sorbitol, di(p-ethylbenzylidene) sorbitol, bis(3,4-dimethyl benzylidene) sorbitol, bis(3,4-diethylbenzylidene) sorbitol and bis(trimethyl-benzylidene) sorbitol. One commercially available nucleating agent is bis(3,4-dimethyl benzylidene) sorbitol.

Optionally, additives can be added to the high density polyethylene. Additives can be added to the high density polyethylene during an extrusion or compounding step, but other suitable known methods will be apparent to a person skilled in the art. The additives can be added as is or added during an extrusion or compounding step. Suitable additives are known in the art and include but are not-limited to antioxidants, phosphites and phosphonites, nitrones, antacids, UV light stabilizers, UV absorbers, metal deactivators, dyes, fillers and reinforcing agents, nano-scale organic or inorganic materials, antistatic agents, lubricating agents such as calcium stearates, slip additives such as erucimide or behenamide, and nucleating agents (including nucleators, pigments or any other chemicals which may provide a nucleating effect to the high density polyethylene). The additives that can be optionally added are typically added in amount of up to 20 weight percent (wt %).

One or more nucleating agent(s) may be introduced into the high density polyethylene by kneading a mixture of the polymer, usually in powder or pellet form, with the nucleating agent, which may be utilized alone or in the form of a concentrate containing further additives such as stabilizers, pigments, antistatics, UV stabilizers and fillers. It should be a material which is wetted or absorbed by the polymer, which is insoluble in the polymer and of melting point higher than that of the polymer, and it should be homogeneously dispersible in the polymer melt in as fine a form as possible (1 to 10 μm). Compounds known to have a nucleating capacity for polyolefins include salts of aliphatic monobasic or dibasic acids or arylalkyl acids, such as sodium succinate, or aluminum phenylacetate; and alkali metal or aluminum salts of aromatic or alicyclic carboxylic acids such as sodium β-naphthoate, or sodium benzoate.

Examples of nucleating agents which are commercially available and which may be added to the high density polyethylene are dibenzylidene sorbital esters (such as the products sold under the trademark Millad 3988™ by Milliken Chemical and Irgaclear™ by Ciba Specialty Chemicals). Further examples of nucleating agents which may added to the high density polyethylene include the cyclic organic structures disclosed in U.S. Pat. No. 5,981,636 (and salts thereof, such as disodium bicyclo [2.2.1] heptene dicarboxylate); the saturated versions of the structures disclosed in U.S. Pat. No. 5,981,636 (as disclosed in U.S. Pat. No. 6,465,551; Zhao et al., to Milliken); the salts of certain cyclic dicarboxylic acids having a hexahydrophtalic acid structure (or “HHPA” structure) as disclosed in U.S. Pat. No. 6,599,971 (Dotson et al., to Milliken); and phosphate esters, such as those disclosed in U.S. Pat. No. 5,342,868 and those sold under the trade names NA-11 and NA-21 by Asahi Denka Kogyo, cyclic dicarboxylates and the salts thereof, such as the divalent metal or metalloid salts, (particularly, calcium salts) of the HHPA structures disclosed in U.S. Pat. No. 6,599,971. For clarity, the HHPA structure generally includes a ring structure with six carbon atoms in the ring and two carboxylic acid groups which are substituents on adjacent atoms of the ring structure. The other four carbon atoms in the ring may be substituted, as disclosed in U.S. Pat. No. 6,599,971. An example is 1,2-cyclohexanedicarboxylicacid, calcium salt (CAS registry number 491589-22-1). Still further examples of nucleating agents which may added to the high density polyethylene include those disclosed in WO2015042561, WO2015042563, WO2015042562 and WO 2011050042.

Many of the above described nucleating agents may be difficult to mix with the high density polyethylene that is being nucleated and it is known to use dispersion aids, such as, for example, zinc stearate, to mitigate this problem.

In an embodiment of the disclosure, the nucleating agents are well dispersed in the high density polyethylene.

In an embodiment of the disclosure, the amount of nucleating agent used is comparatively small—from 5 to 3000 parts by million per weight (based on the weight of the high density polyethylene) so it will be appreciated by those skilled in the art that some care is taken to ensure that the nucleating agent is well dispersed. In an embodiment of the disclosure, the nucleating agent is added in finely divided form (less than 50 microns, or for example less than 10 microns) to the high density polyethylene to facilitate mixing. In some embodiments, this type of “physical blend” (i.e., a mixture of the nucleating agent and the resin in solid form) is generally preferable to the use of a “masterbatch” of the nucleator (where the term “masterbatch” refers to the practice of first melt mixing the additive—the nucleator, in this case—with a small amount of the high density polyethylene—then melt mixing the “masterbatch” with the remaining bulk of the high density polyethylene).

In an embodiment of the disclosure, an additive such as nucleating agent may be added to the high density polyethylene by way of a “masterbatch”, where the term “masterbatch” refers to the practice of first melt mixing the additive (e.g., a nucleator) with a small amount of the high density polyethylene, followed by melt mixing the “masterbatch” with the remaining bulk of the high density polyethylene.

In an embodiment of the disclosure, the high density polyethylene further includes a nucleating agent or a mixture of nucleating agents.

Since the high density polyethylene is used in bottle closure assemblies typically used for food contact applications, the additive package, if present, should meet the appropriate food regulations, such as, the FDA regulations in the United States.

In an embodiment of the disclosure, the high density polyethylene described above is used in the formation of molded articles. For example, articles formed by continuous compression molding and injection molding are contemplated. Such articles include, for example, bottle closure assemblies, caps, hinged caps, screw caps, closures and hinged closures for bottles.

The high density polyethylene described above is used in the formation of bottle closure assemblies. For example, bottle closure assemblies formed in part on in whole by compression molding and/or injection molding are contemplated.

In one embodiment, the bottle closure assembly including the high density polyethylene described above has good organoleptic properties. The bottle closure assemblies are well suited for sealing bottles, containers and the like, for examples bottles that may contain drinkable water, and other foodstuffs, including but not limited to liquids that are pressurized (e.g. carbonated beverages or appropriately pressurized drinkable liquids). The bottle closure assemblies may also be used for sealing bottles containing drinkable water or non-carbonated beverages (e.g. juice). Other applications, include bottle closure assemblies for bottles and containers containing foodstuffs, such as for example ketchup bottles and the like.

The bottle closure assemblies of the current disclosure can be made according to any known method, including for example injection molding and/or compression molding techniques that are well known to persons skilled in the art. Hence, in an embodiment of the disclosure a bottle closure assembly including the high density polyethylene (defined above) is prepared with a process including at least one compression molding step and/or at least one injection molding step.

Further non-limiting details of the disclosure are provided in the following examples. The examples are presented for the purpose of illustrating selected embodiments of this disclosure, it being understood that the examples presented do not limit the claims presented.

EXAMPLES

Melt indexes, I₂, I₅, I₆ and I₂₁ for the polyethylene composition were measured according to ASTM D1238 (when conducted at 190° C., using a 2.16 kg, a 5 kg, a 6.48 kg and a 21 kg weight respectively).

M_(n), M_(w), and M_(z) (g/mol) were determined by high temperature Gel Permeation Chromatography with differential refractive index detection using universal calibration (e.g. ASTM-D6474-99). GPC data was obtained using an instrument sold under the trade name “Waters 150c”, with 1,2,4-trichlorobenzene as the mobile phase at 140° C. The samples were prepared by dissolving the polymer in this solvent and were run without filtration. Molecular weights are expressed as polyethylene equivalents with a relative standard deviation of 2.9% for the number average molecular weight (“Mn”) and 5.0% for the weight average molecular weight (“Mw”). The molecular weight distribution (MWD) is the weight average molecular weight divided by the number average molecular weight, M_(W)/M_(n). The z-average molecular weight distribution is M_(z)/M_(n). Polymer sample solutions (1 to 2 mg/mL) were prepared by heating the polymer in 1,2,4-trichlorobenzene (TCB) and rotating on a wheel for 4 hours at 150° C. in an oven. The antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT) was added to the mixture in order to stabilize the polymer against oxidative degradation. The BHT concentration was 250 ppm. Sample solutions were chromatographed at 140° C. on a PL 220 high-temperature chromatography unit equipped with four Shodex columns (HT803, HT804, HT805 and HT806) using TCB as the mobile phase with a flow rate of 1.0 mL/minute, with a differential refractive index (DRI) as the concentration detector. BHT was added to the mobile phase at a concentration of 250 ppm to protect the columns from oxidative degradation. The sample injection volume was 200 mL. The raw data were processed with Cirrus GPC software. The columns were calibrated with narrow distribution polystyrene standards. The polystyrene molecular weights were converted to polyethylene molecular weights using the Mark-Houwink equation, as described in the ASTM standard test method D6474.

Primary melting peak (° C.), heat of fusion (J/g) and crystallinity (%) was determined using differential scanning calorimetry (DSC) as follows: the instrument was first calibrated with indium; after the calibration, a polymer specimen is equilibrated at 0° C. and then the temperature was increased to 200° C. at a heating rate of 10° C./min; the melt was then kept isothermally at 200° C. for five minutes; the melt was then cooled to 0° C. at a cooling rate of 10° C./min and kept at 0° C. for five minutes; the specimen was then heated to 200° C. at a heating rate of 10° C./min. The DSC Tm, heat of fusion and crystallinity are reported from the 2^(nd) heating cycle.

The short chain branch frequency (SCB per 1000 carbon atoms) of the polyethylene composition was determined by Fourier Transform Infrared Spectroscopy (FTIR) as per the ASTM D6645-01 method. A Thermo-Nicolet 750 Magna-IR Spectrophotometer equipped with OMNIC version 7.2a software was used for the measurements. Unsaturations in the polyethylene composition were also determined by Fourier Transform Infrared Spectroscopy (FTIR) as per ASTM D3124-98. Comonomer content can also be measured using ¹³C NMR techniques as discussed in Randall, Rev. Macromol. Chem. Phys., C29 (2&3), p 285; U.S. Pat. No. 5,292,845 and WO 2005/121239.

Polyethylene density (g/cm³) was measured according to ASTM D792.

Hexane extractables were determined according to ASTM D5227.

Shear viscosity was measured by using a Kayeness WinKARS Capillary Rheometer (model #D5052M-115). For the shear viscosity at lower shear rates, a die having a die diameter of 0.06 inch and L/D ratio of 20 and an entrance angle of 180 degrees was used. For the shear viscosity at higher shear rates, a die having a die diameter of 0.012 inch and L/D ratio of 20 was used.

To determine CDBI(50), a solubility distribution curve is first generated for the polyethylene. This is accomplished using data acquired from the TREF technique. This solubility distribution curve is a plot of the weight fraction of the copolymer that is solubilized as a function of temperature. This is converted to a cumulative distribution curve of weight fraction versus comonomer content, from which the CDBI(50) is determined by establishing the weight percentage of a copolymer sample that has a comonomer content within 50% of the median comonomer content on each side of the median (See WO 93/03093 and U.S. Pat. No. 5,376,439). The CDBI(25) is determined by establishing the weight percentage of a copolymer sample that has a comonomer content within 25% of the median comonomer content on each side of the median

The temperature rising elution fractionation (TREF) method used herein was as follows. Polymer samples (50 to 150 mg) were introduced into the reactor vessel of a crystallization-TREF unit (Polymer ChAR™). The reactor vessel was filled with 20 to 40 ml 1,2,4-trichlorobenzene (TCB), and heated to the desired dissolution temperature (e.g., 150° C.) for 1 to 3 hours. The solution (0.5 to 1.5 ml) was then loaded into the TREF column filled with stainless steel beads. After equilibration at a given stabilization temperature (e.g., 110° C.) for 30 to 45 minutes, the polymer solution was allowed to crystallize with a temperature drop from the stabilization temperature to 30° C. (0.1 or 0.2° C./minute). After equilibrating at 30° C. for 30 minutes, the crystallized sample was eluted with TCB (0.5 or 0.75 mL/minute) with a temperature ramp from 30° C. to the stabilization temperature (0.25 or 1.0° C./minute). The TREF column was cleaned at the end of the run for 30 minutes at the dissolution temperature. The data were processed using Polymer ChAR software, Excel spreadsheet and TREF software developed in-house.

High temperature GPC equipped with an online FTIR detector (GPC-FTIR) was used to measure the comonomer content as the function of molecular weight.

Plaques molded from the polyethylenes were tested according to the following ASTM methods: Bent Strip Environmental Stress Crack Resistance (ESCR) at Condition B at 10% and 100% IGEPAL at 50° C., ASTM D1693; notched Izod impact properties, ASTM D256; Flexural Properties, ASTM D 790; Tensile properties, ASTM D 638; Vicat softening point, ASTM D 1525; Heat deflection temperature, ASTM D 648.

Dynamic mechanical analyses were carried out with a rheometer, namely Rheometrics Dynamic Spectrometer (RDS-II) or Rheometrics SR5 or ATS Stresstech, on compression molded samples under nitrogen atmosphere at 190° C., using 25 mm diameter cone and plate geometry. The oscillatory shear experiments were done within the linear viscoelastic range of strain (10% strain) at frequencies from 0.05 to 100 rad/s. The values of storage modulus (G′), loss modulus (G″), complex modulus (G*) and complex viscosity (η*) were obtained as a function of frequency. The same rheological data can also be obtained by using a 25 mm diameter parallel plate geometry at 190° C. under nitrogen atmosphere.

Example 1 is a high density polyethylene homopolymer having a melt index I₂ of 5 g/10 min, a density of 0.960 g/cm³, and a molecular weight distribution Mw/Mn of 2.67. The unimodal polyethylene homopolymer of Example 1, was made using a Ziegler-Natta catalyst in a solution olefin polymerization process. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2907. A GPC profile for the resin is given in FIG. 8.

Example 2 is a high density polyethylene copolymer having a melt index I₂ of 6.7 g/10 min, a density of 0.954 g/cm³, and a molecular weight distribution Mw/Mn of 2.72. The unimodal polyethylene copolymer of Example 2, was made using a Ziegler-Natta catalyst in a solution olefin polymerization process. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2807. A GPC profile for the resin is given in FIG. 9.

Example 3 is a high density polyethylene homopolymer having a melt index I₂ of 7 g/10 min, a density of 0.961 g/cm³, and a molecular weight distribution Mw/Mn of 2.99. The unimodal polyethylene homopolymer of Example 3, was made using a Ziegler-Natta catalyst in a solution olefin polymerization process. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2908. A GPC profile for the resin is given in FIG. 10.

Example 4 is a high density polyethylene copolymer having a melt index I₂ of 17 g/10 min, a density of 0.951 g/cm³, and a molecular weight distribution Mw/Mn of 2.72. The unimodal polyethylene copolymer of Example 4, was made using a Ziegler-Natta catalyst in a solution olefin polymerization process. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2710. A GPC profile for the resin is given in FIG. 11.

Example 5 is a high density polyethylene copolymer having a melt index I₂ of 32 g/10 min, a density of 0.951 g/cm³, and a molecular weight distribution, Mw/Mn of 2.88, and which is made using a Ziegler-Natta catalyst in a solution olefin polymerization process. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR® 2712. A GPC profile for the resin is given in FIG. 12.

Further details of the high density polyethylenes of Examples 1-5 are shown in Table 1, along with their plaque data.

TABLE 1 Resin and Plaque Properties Example No. 1 2 3 4 5 Density (g/cm³) 0.960 0.954 0.961 0.951 0.951 Rheology/Flow Properties Melt Index I₂ (g/10 min) 5 6.7 7 17 32 Melt Flow Ratio (I₂₁/I₂) 27 28.2 25.7 24 22.7 Stress Exponent 1.32 1.33 1.29 1.27 1.24 Shear Viscosity at 10⁵ s⁻¹ 7.00 7.4 6.7 6.00 5.90 (240° C., Pa-s) Shear Viscosity Ratio 4.21 3.82 1.85 1.66 1.49 η (10 s⁻¹)/η (1000 s⁻¹) at 240° C. Shear Viscosity Ratio 75 59.4 60 19.62 η (100 s⁻¹)/η (100000 s⁻¹) at 240° C. GPC - conventional M_(n) 27405 26005 21623 19622 14928 M_(w) 73262 70836 65028 53372 43003 M_(z) 183608 185530 174598 123854 95318 Polydispersity Index 2.67 2.72 3.03 2.72 2.88 (M_(w)/M_(n)) M_(z)/M_(w) 2.51 2.62 2.32 2.22 Branch Frequency - FTIR (uncorrected for chain end —CH₃) Uncorrected <0.5 0.7 1.3 SCB/1000 C Uncorrected comonomer content (mol %) Internal unsaturation 0.030 0.040 0.03 0.060 0.080 (/1000 C) Side chain 0.030 0.030 0.03 0.050 0.050 unsaturation (/1000 C) Terminal unsaturation 0.720 0.720 0.71 0.790 0.850 (/1000 C) Comonomer ID — 1-butene — 1-butene 1-butene TREF — 78.8 — 72.8 68.7 CDBI₅₀ (%) TREF — 66.9 — 59.6 50.5 CDBI₂₅ (%) DSC Primary Melting Peak 132.13 130.04 132.1 127.75 126.99 (° C.) Heat of Fusion (J/g) 226.30 215.7 229.8 205.40 210.40 Crystallinity (%) 78.05 74.37 79.2 70.82 72.55 Environmental Stress Crack Resistance ESCR Cond. B at 3 3 3 2 0 100% (hours) ESCR Cond. B at 10% 4 3 3 1 0 (hours) Flexural Properties (Plaques) Flex Secant Mod. 2% 1018 886 1075 787 786 (MPa) Impact Properties (Plaques) Izod Impact (ft-lb/in) 0.80 1.13 1.2 0.76 0.66 Other properties Hexane Extractables 0.21 0.24 0.23 0.33 0.43 (%) VICAT Soft. Pt. (° C.) - 129 127 129.5 123.9 122 Plaque Heat Deflection Temp. 75 74 83.6 65.4 66 [° C.] @ 66 PSI

Neutron Activation Analysis (NAA)

Neutron Activation Analysis, hereafter NAA, was used to determine catalyst residues in ethylene polymers and was performed as follows. A radiation vial (composed of ultrapure polyethylene, 7 mL internal volume) was filled with a polyethylene polymer product sample and the sample weight was recorded. Using a pneumatic transfer system the sample was placed inside a SLOWPOKE™ nuclear reactor (Atomic Energy of Canada Limited, Ottawa, Ontario, Canada) and irradiated for 30 to 600 seconds for short half-life elements (e.g., Ti, V, Al, Mg, and Cl) or 3 to 5 hours for long half-life elements (e.g. Zr, Hf, Cr, Fe and Ni). The average thermal neutron flux within the reactor was 5×10¹¹/cm²/s. After irradiation, samples were withdrawn from the reactor and aged, allowing the radioactivity to decay; short half-life elements were aged for 300 seconds or long half-life elements were aged for several days. After aging, the gamma-ray spectrum of the sample was recorded using a germanium semiconductor gamma-ray detector (Ortec model GEM55185, Advanced Measurement Technology Inc., Oak Ridge, Tenn., USA) and a multichannel analyzer (Ortec model DSPEC Pro). The amount of each element in the sample was calculated from the gamma-ray spectrum and recorded in parts per million relative to the total weight of the polyethylene polymer sample. The N.A.A. system was calibrated with Specpure standards (1000 ppm solutions of the desired element (greater than 99% pure)). One mL of solutions (elements of interest) were pipetted onto a 15 mm×800 mm rectangular paper filter and air dried. The filter paper was then placed in a 1.4 mL polyethylene irradiation vial and analyzed by the N.A.A. system. Standards are used to determine the sensitivity of the N.A.A. procedure (in counts/pg).

The high density polyethylenes of Examples 1-4 are as described above. Examples 6-9 are commercially available polymers having a melt index, I₂ ranging from about 1.5 to about 11.0 g/10 min and densities ranging from about 0.951 g/cm³ to about 0.955 g/cm³.

TABLE 2 NAA of Polyethylene Polymers Example Al (ppm) Cl (ppm) Mg (ppm) Ti (ppm) 1 0.96 0.14 <2 0.19 2 0.58 0.1 <2 0.69 3 0.511 0.074 <1 0.288 4 0.19 0.11 <1 0.16 6 66.3 20.2 3.61 7.27 7 65.2 32.6 4.05 12.19 8 25.1 9.54 2.89 0.923 9 26.2 11.3 3.97 1.01

The data provided in Table 2 shows that the polymers of Examples 1-4 have much reduced residual catalyst component levels (e.g. aluminum, chlorine, magnesium and titanium) when compared to several other commercially available products (Examples 6 through 9). Compare for example, Examples 1-4 which have less than 1 ppm of aluminum (Al), and less than 0.7 ppm of titanium (Ti) present (where “ppm” is parts per million of element per mass of polymer, e.g. milligrams of element/kilograms of polymer) with Examples 6-9 which have Al levels of from about 25 ppm to about 66 ppm, and Ti levels of from about 1 to about 12 ppm. Examples 1-4 also have much lower levels of chlorine (Cl) and magnesium (Mg), which don't exceed about 0.15 ppm and 2 ppm respectively.

For end use applications, especially those which may come in contact with foodstuff it may be desirable to employ products having lower levels of catalyst component residues. Lower catalyst residues may lead to better organoleptic properties and help preserve the original taste and odor of the packaged contents.

The high density polyethylene described above can be used in the formation of bottle closure assemblies. For example, bottle closure assemblies formed in part on in whole by compression molding and/or injection molding are contemplated.

In one embodiment, the bottle closure assembly includes the high density polyethylene described above and has good organoleptic properties. Hence, the bottle closure assemblies are well suited for sealing bottles, containers and the like, for examples bottles that may contain drinkable water, and other foodstuffs, including but not limited to liquids that are pressurized or non-pressurized.

In an embodiment of the disclosure a bottle closure assembly including a high density polyethylene defined as above is prepared with a process including at least one compression molding step and/or at least one injection molding step.

Preparation of a Tether Proxy for Deformation Testing

In order to provide a proxy of a tether portion which can be analyzed under conditions of shear, tear and tensile deformation, a closure (see FIGS. 13A and 13B) was compression molded as described below and then a tamper evident band, 10* (a proxy for a retaining means portion, 10) was formed by folding in and cutting the bottom circular edge of the closure using a folding/slitting machine with a modified blade, so that a tamper evident band (10*) which was joined to the cap portion (1) by several narrow (“pin” like) connecting sections (marked by the frangible line, 9 in FIGS. 13A and 13B) and one larger continuous section (i.e. continuous with a portion of the cap portion side wall), with the larger continuous section serving as a proxy for a tether (the area marked as 40 in FIGS. 13A and 13B). The larger continuous section or “tether proxy” section was designed to have an arcuate length of 6 mm. The “tether proxy” section had a cross-sectional width (or thickness) of 0.6 mm as determined by the dimensions of the closure mold used for the compression molding process (see below). The “tether proxy” section, or simply “tether proxy” 40 was then subjected to shear and tear deformations and to tensile deformation using a toque tester unit and tensile tester unit respectively (see below).

Method of Making a Closure by Compression Molding

A SACMI Compression molding machine (model CCM24SB) and a PCO (plastic closure only) 1881 carbonated soft drink (CSD) closure mold was used to prepare the closures. Depending on material density, melt index (I₂) and chosen plug size, the closure weight varied between 2.15 g and 2.45 grams, with the process conditions adjusted to target a closure having a weight of about 2.3 grams. During the closure preparation process, the overall closure dimensions, such as, for the example, the closure diameter and the closure height were measured and maintained within desired “quality-controlled” specifications. Closures with poor circularity or with significant deformation away from the pre-defined specifications were rejected by an automatic vision system installed on the compression molding machine. Once the closure had been compression molded, a tamper evident band, inclusive of one larger continuous section (a proxy for a tether portion) was cut into the closure bottom edge using a folding/slitting machine fitted with a modified blade. Both experimental and simulated data confirmed that 99% of any closure weight differences were due to differences in the top panel thickness (of the cap portion, see FIG. 13A) for each of the compression molded closures. For example, in the closures prepared by compression molding, the top panel thickness values of closures having a weight ranging from 2.15 grams to 2.45 grams were found to be slightly different, but each of the closure side wall thicknesses were found to be identical. As a result, any small differences in the compression molded cap weight were expected to have no impact on the dimensions of the tamper evident band or the tether proxy section (see above): in each case, the tether proxy had an arcuate length of 6 mm and a cross-sectional thickness of 0.6 mm.

Type 1 closures were compression molded from a high density, unimodal polyethylene copolymer (Example 2) having a melt index I₂ of 6.7 g/10 min, a density of 0.954 g/cm³, and a molecular weight distribution Mw/Mn of 2.72. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2807.

Type 2 closures were compression molded from a high density, unimodal polyethylene homopolymer (Example 3) having a melt index I₂ of 7 g/10 min, a density of 0.961 g/cm³, and a molecular weight distribution Mw/Mn of 2.99. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2908.

Type 3 closures were compression molded from a high density, unimodal polyethylene copolymer (Example 4) having a melt index I₂ of 17 g/10 min, a density of 0.951 g/cm³, and a molecular weight distribution Mw/Mn of 2.72. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2710.

Type 4 closures were compression molded from a high density, unimodal polyethylene copolymer (Example 5) having a melt index I₂ of 32 g/10 min, a density of 0.951 g/cm³, and a molecular weight distribution, Mw/Mn of 2.88. This resin is commercially available from NOVA Chemicals Corporation as SCLAIR 2712.

The compression molding conditions used to make each closure type are provided in Table 3.

TABLE 3 Compression Molding Processing Conditions Closure Type No. 1 2 3 4 Closure Weight (g) 2.36 2.32 2.36 2.39 BT1 Temp (° C.) 160 164 163 163 BT2 Temp (° C.) 164 163 164 164 BT3 Temp (° C.) 165 164 163 163 BT4 Temp (° C.) 165 170 161 161 BT6 Temp (° C.) 170 185 170 170 BT7 Temp (° C.) 185 184 187 187 BT8 Temp (° C.) 185 184 184 184 BT9 Temp (° C.) 185 170 184 184 BT15 Temp (° C.) 170 165 170 170 BT16 Temp (° C.) 165 175 165 165 BT17 Temp (° C.) 175 175 174 174 Metering Pump Set Press 50 50 50 50 (bar) Metering Pump Actual Press 51 51 50 50 1 (bar) IN Metering Pump Actual Press 52.9 53 28 30.6 2 (bar) OUT Pump Speed (%) 57 56 56 57 Hydraulic Operating Temp 46 47 46 46 (° C.) Punch Cooling BT18 (° C.) 20 20 20 20 Cavity Cooling BT19 (° C.) 20 20 20 20 Ausiliari Cooling BT20 (° C.) 30 30 30 30

Shear Deformation of a Tether Proxy

A TMS 5000 Torque Tester unit manufactured by Steinfurth was used to carry out the tether proxy shear deformation testing. The unit was adjusted to operate in “removal torque mode”. A closure having a tether proxy section (area 40 in FIGS. 13A and 13B) with a 6 mm arcuate length and a 0.6 mm cross-sectional width connecting a cap portion (1) to a tamper evident band 10* (a proxy for a retaining means portion, 10) and suitable for mating with a PCO 1881 bottle finish was employed. Prior to testing, the tamper evident band (10*) was unfolded and then almost entirely removed, by cutting through the tamper evident band at a distance of approximately 2 mm from each end of the tether proxy section. The remaining portion of the tamper evident band (as shown in FIGS. 14A and 14B) then, includes the tether proxy section having an arcuate length of 6 mm, and a further 2 mm arcuate length section on either side of the tether proxy section, all of which has a cross sectional width of 0.6 mm. Adding 2 mm to either side of the tether proxy section provides a larger surface area to grip when carrying out the shear deformation testing. In order to support the closure for testing in the Torque Tester unit, a modified tubular preform was used (item 45 in FIG. 14B). The tubular pre-form 45 was made of polyethylene terephthalate and was modified to have smooth outer walls. Following this, a brass rod (50), having a diameter which fit snuggly within the preform (45) was inserted as a plug to afford rigidity to the pre-form and to prevent its deformation during testing. Next, the closure was placed on top of the pre-form and the remaining section of the tamper evident band (10*) was clamped to the preform using vice grips. The closure and preform were then mounted within the Torque Tester. The cap portion (1) was gripped from above within a suitably designed chuck and rotated at a removal torque speed of 0.8 rpm, relative to the clamped section of the tamper evident band, using the Torque Tester. The shear strength of the tether proxy (40) is defined as the maximum torque (in inches·pounds) required to separate the cap portion (1) from the remaining section of the tamper evident band section (10*) by breaking the tether proxy (40). The reported shear strength in Table 4 is the average of at least 5 such shear deformation tests.

Tear Deformation of a Tether Proxy

A TMS 5000 Torque Tester unit manufactured by Steinfurth was used to carry out the tether proxy shear deformation testing. The unit was adjusted to operate in “removal torque mode”. A closure having a tether proxy section (area 40 in FIGS. 13A and 13B) with a 6 mm arcuate length and a 0.6 mm cross-sectional width connecting a cap portion (1) to a tamper evident band 10* (a proxy for a retaining means portion, 10) and suitable for mating with a PCO 1881 bottle finish was employed. In order to support the closure for testing in the Torque Tester unit, a modified tubular pre-form was used (item 45 in FIG. 14C). The tubular pre-form 45 was made of polyethylene terephthalate and was modified to have smooth outer walls. Following this, a brass rod (50), having a diameter which fit snuggly within the pre-form (45) was inserted as a plug to afford rigidity to the pre-form and to prevent its deformation during testing. Next, the closure was placed on top of the preform. Prior to testing, the tamper evident band (10*) was deflected downward (on the opposite side of the tether proxy section) and away from the cap portion (1) as is shown in FIG. 14C. The downward deflection breaks all the narrow pin sections (the frangible line 9 in FIGS. 13A and 13B) joining the top edge of the tamper evident band to the lower edge of the cap portion while leaving the larger continuous section, the tether proxy section (40), intact. The tamper evident band (10*) is deflected downward and away from the cap portion (1) until the top edge of the tamper evident band makes an angle with the lower edge of the cap portion of about 27 degrees, while the tether portion remains intact along its 6 mm arcuate length (see FIG. 14C). The tamper evident band (10*) was then clamped to the pre-form in this downwardly deflected position using vice grips. The closure and pre-form were then mounted within the Torque Tester. The cap portion (1) was gripped from above within a suitably designed chuck and rotated at a removal torque speed of 0.8 rpm, relative to the clamped tamper evident band (10*), using the Torque Tester. The tear strength of the tether proxy (40) is defined as the maximum torque (in inches·pounds) required to separate the cap portion (1) from the downwardly deflected tamper evident band (10*) by breaking the tether proxy (40). The reported tear strength in Table 4 is the average of at least 5 such tear deformation tests.

Tensile Deformation of a Tether Proxy

Tensile deformation tests were performed using a tensile machine (an Instron 4204 universal tester, with a 1 KN (225 lbf) capacity load cell) with the crosshead velocity set at 50 mm/min. A closure having a tether proxy section (area 40 in FIGS. 13A and 13B) with a 6 mm arcuate length and a 0.6 mm cross-sectional width connecting a cap portion (1) to a tamper evident band 10* (a proxy for a retaining means portion, 10) and suitable for mating with a PCO 1881 bottle finish was employed. Prior to testing, the tamper evident band (10*) was unfolded and then almost entirely removed, by cutting through the tamper evident band at a distance of approximately 2 mm from each end of the tether proxy section (see FIGS. 14A, 15A and 15B). The remaining portion of the tamper evident band (as shown in FIGS. 14A, 15A and 15B) then, includes the tether proxy section having an arcuate length of 6 mm, and a further 2 mm arcuate length section on either side of the tether proxy section, all of which has a cross sectional width of 0.6 mm. Adding 2 mm to either side of the tether proxy section provides a larger surface area to grip when carrying out the tensile deformation testing. For the tensile deformation test, most of the cap portion (1) was similarly cut away, leaving only a section of the cap portion side wall connected to the what was left of the tamper evident band (see FIGS. 15A and 15B). This “cut away” section of the closure was then mounted in the tensile tester, with the remaining cap portion side wall and the remaining tamper evident band each being secured with 0.5-inch wide steel serrated grips at a 0.25-inch grip separation. During the tensile testing, the remaining section of the cap portion (1) and the remaining section of the tamper evident band (10*) were drawn apart vertically. The tensile strength of the tether proxy (40) is defined as the maximum load (in grams·force, gf) required to separate the remaining cap portion (1) from the remaining tamper evident band section (10*) by breaking the tether proxy (40). The reported tensile strength in Table 4 is the average of at least 5 such tensile deformation tests.

TABLE 4 Average Shear, Tear and Tensile Deformation of a Tether Proxy Closure Type No. 1 2 3 4 Shear Strength 11.43 10.25 9.94 9.43 (inches.pounds) Tear Strength 9.89 10.68 9.78 9.18 (inches.pounds) Tensile Strength 16183 14700 13231 12800 (grams.force)

A person skilled in the art will recognize from the data provided in Table 4, that a tether proxy made using the polyethylene of Example 2, has a better ability to resist shear and tensile deformations, while the tear deformation is not statistically different (beyond a 95% confidence level) when compared to a tether proxy made with the polyethylene of Example 5, which has a higher melt index, I₂. A tether proxy made using the polyethylene of Example 3, has a better ability to resist tear and tensile deformations, while the shear deformation is not statistically different (beyond a 95% confidence level) when compared to a tether proxy made with the polyethylene of Example 5, which has a higher melt index, I₂. A tether proxy made using the polyethylene of Example 4, has shear, tear and tensile deformations which are not statistically different (beyond a 95% confidence level) from that of a tether proxy made using the polyethylene of Example 5. The data thus provides further evidence that some of the high density polyethylene described herein may be useful in the production of bottle closure assemblies, by preventing facile separation of a cap portion from a retaining means portion or from a bottle, and by generally helping to prevent loss or disassociation of a cap portion (a potential plastic waste stream) from a bottle, where the cap portion could otherwise contribute to environmental waste concerns.

The present disclosure has been described with reference to certain details of particular embodiments thereof. It is not intended that such details be regarded as limitations upon the scope of the disclosure except insofar as and to the extent that they are included in the accompanying claims. 

We claim:
 1. A bottle closure assembly comprising: a cap portion, a tether portion, and a retaining means portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and where the tether portion connects at least one point on the cap portion to at least one point on the retaining means portion, wherein the cap portion, optionally the tether portion, and optionally the retaining means portion comprise a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.
 2. A bottle closure assembly comprising: a cap portion, an elongated tether portion, and a retaining means portion, the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the elongated tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion, wherein the cap portion, optionally the elongated tether portion, and optionally the retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.
 3. A bottle closure assembly comprising: an integrally molded: cap portion, tether portion, and retaining means portion; the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion; wherein the integrally molded: cap portion, tether portion and retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.
 4. A bottle closure assembly comprising: an integrally molded: cap portion, elongated tether portion, and retaining means portion; the cap portion being molded to reversibly engage and cover a bottle opening, the retaining means portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the elongated tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining means portion; wherein the integrally molded: cap portion, elongated tether portion and retaining means portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.
 5. A bottle closure assembly comprising: an integrally molded: cap portion, elongated tether portion, and retaining collar portion; the cap portion being molded to reversibly engage and cover a bottle opening, the retaining collar portion being molded to irreversibly engage a bottle neck or an upper portion of a bottle, and the elongated tether portion being molded to connect at least one point on the cap portion to at least one point on the retaining collar portion; wherein the integrally molded: cap portion, elongated tether portion and retaining collar portion are made from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.
 6. A bottle closure assembly comprising: a closure portion, an elongated tether portion, and a retaining collar portion, the closure portion being molded to reversibly engage and cover a bottle opening, the elongated tether portion comprising a tether strip which is frangibly connected along a portion of its upper edge to a descending annular edge of the closure portion and which is frangibly connected along a portion of its lower edge to an upper annular edge of the retaining collar portion, the tether strip being integrally formed with and connected at one end to at least one point on the closure portion and integrally formed with and connected at another end to at least one point on the retaining collar portion, the frangible sections being breakable when the closure portion is removed from a bottle opening, but where the closure portion remains connected to the retaining collar via the tether strip; wherein the cap portion, the elongated tether portion and the retaining collar portion are integrally molded from a high density polyethylene which is not a polymer blend and has a density of from 0.940 to 0.965 g/cm³, a melt index, I₂ of less than 35 g/10 min, a molecular weight distribution, M_(W)/M_(n) of less than 5.0, and a unimodal profile in a GPC chromatograph.
 7. The bottle closure assembly of claim 1 wherein the high density polyethylene which is not a polymer blend has a melt index, I₂ of less than 15 g/10 min.
 8. The bottle closure assembly of claim 2 wherein the high density polyethylene which is not a polymer blend has a melt index, I₂ of less than 15 g/10 min.
 9. The bottle closure assembly of claim 3 wherein the high density polyethylene which is not a polymer blend has a melt index, I₂ of less than 15 g/10 min.
 10. The bottle closure assembly of claim 4 wherein the high density polyethylene which is not a polymer blend has a melt index, I₂ of less than 15 g/10 min.
 11. The bottle closure assembly of claim 5 wherein the high density polyethylene which is not a polymer blend has a melt index, I₂ of less than 15 g/10 min.
 12. The bottle closure assembly of claim 6 wherein the high density polyethylene which is not a polymer blend has a melt index, I₂ of less than 15 g/10 min.
 13. The bottle closure assembly of claim 1 wherein the high density polyethylene which is not a polymer blend has a molecular weight distribution, M_(W)/M_(n) from about 2.0 to about 4.5.
 14. The bottle closure assembly of claim 2 wherein the high density polyethylene which is not a polymer blend has a molecular weight distribution, M_(W)/M_(n) from about 2.0 to about 4.5.
 15. The bottle closure assembly of claim 3 wherein the high density polyethylene which is not a polymer blend has a molecular weight distribution, M_(W)/M_(n) from about 2.0 to about 4.5.
 16. The bottle closure assembly of claim 4 wherein the high density polyethylene which is not a polymer blend has a molecular weight distribution, M_(W)/M_(n) from about 2.0 to about 4.5.
 17. The bottle closure assembly of claim 5 wherein the high density polyethylene which is not a polymer blend has a molecular weight distribution, M_(W)/M_(n) from about 2.0 to about 4.5.
 18. The bottle closure assembly of claim 6 wherein the high density polyethylene which is not a polymer blend has a molecular weight distribution, M_(W)/M_(n) from about 2.0 to about 4.5. 